U.S. patent number 10,004,579 [Application Number 14/284,037] was granted by the patent office on 2018-06-26 for method of manufacturing a dental superstructure.
This patent grant is currently assigned to Kulzer GmbH. The grantee listed for this patent is Kulzer GmbH. Invention is credited to Sture Benzon, Per Olof Leike.
United States Patent |
10,004,579 |
Benzon , et al. |
June 26, 2018 |
Method of manufacturing a dental superstructure
Abstract
A dental superstructure, and a manufacturing method thereof,
comprising a screw-channel (1), through which screw-channel a screw
member is to be inserted, and a screw member seat (3), for
providing support to the head of said screw member during fixation
of said dental superstructure to a spacer element or an implant
(5), are provided. Said dental superstructure is provided with a
central axis of said screw-channel (1) and a central axis of said
second mouth (4) that at least partly do not coincide. A
manufacturing method thereof, a screw-member, and a screwdriver are
also provided.
Inventors: |
Benzon; Sture (Helsingborg,
SE), Leike; Per Olof (Billdal, SE) |
Applicant: |
Name |
City |
State |
Country |
Type |
Kulzer GmbH |
Hanau |
N/A |
DE |
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Assignee: |
Kulzer GmbH (Hanau,
DE)
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Family
ID: |
41003393 |
Appl.
No.: |
14/284,037 |
Filed: |
May 21, 2014 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20150072311 A1 |
Mar 12, 2015 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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12438683 |
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PCT/SE2007/050565 |
Aug 22, 2007 |
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60919041 |
Mar 20, 2007 |
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Foreign Application Priority Data
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Aug 25, 2006 [SE] |
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0601754 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61C
8/0048 (20130101); A61C 8/0051 (20130101); A61C
8/0089 (20130101); A61C 8/0068 (20130101); A61C
8/005 (20130101); A61C 13/08 (20130101); Y10T
29/49567 (20150115); Y10T 408/03 (20150115) |
Current International
Class: |
A61C
8/00 (20060101); A61C 13/08 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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Apr 2005 |
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Mar 1991 |
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EP |
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0 580 945 |
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Feb 1994 |
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EP |
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0 987 994 |
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Dec 2005 |
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EP |
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1 201 856 |
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Aug 1970 |
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GB |
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1-151453 |
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Jun 1989 |
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JP |
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2001-0091658 |
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Oct 2001 |
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KR |
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2001 0091658 |
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Oct 2001 |
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KR |
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20010091658 |
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Oct 2001 |
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KR |
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2006 0012036 |
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Feb 2006 |
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KR |
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20060012036 |
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Feb 2006 |
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KR |
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506 850 |
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Feb 1998 |
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SE |
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WO 98/47441 |
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Oct 1998 |
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WO |
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WO 01/70127 |
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Sep 2001 |
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WO |
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WO 2005107988 |
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Nov 2005 |
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WO |
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Other References
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Feb. 17, 2015 (7 pages). cited by applicant .
Balaji. "Textbook of Oral Maxillofacial Surgery: Section IV: Minor
Oral Surgical Procedures." Elsevier India, 2007 pp. 311-315. cited
by applicant .
Heasman. "Second Edition: Master Dentistry: vol. 2: Restorative
Dentistry, Paediatric Dentistry and Orthodontics." Churchill
Livingston El Sevier. 2003. pp. 133. cited by applicant .
Heliden et al. "The Cresco Bridge and Implant Concept: Presentation
of a Technology for Fabrication of Abutment-Free Passively Fitting
Superstructures." The Intnl J. of Periodontics & Restorative
Dentistry. vol. 25, No. 1. 2005. pp. 89-94. cited by applicant
.
Hellden et al. "The Cresco FPD and Implant Concept: Presentation of
a Technology for Fabrication of Abutment-Free, Passively Fitting
Superstructures." International J. of Periodontics &
Restorative Dentistry. vol. 25. Nov. 1, 2005. pp. 2-8. cited by
applicant .
Malik. "2.sup.nd Edition: Textbook of Oral and Maxillofacial
Surgery." Jaypee Brothers Medical Publishers (P) Ltd 2008. pp.
745-746. cited by applicant .
Misch. "Contemporary Implant Dentistry: Third Edition." Mosby El
Sevier. 2008. pp. 31-32. cited by applicant .
Misch. "Dental Implant Prosthetics." El Sevier Mosby. 2005. pp.
37-38. cited by applicant .
Ortorp et al. "Clinical experiences with laser-welded titanium
frameworks supported by implants in the edentulous mandible: a
5-year follow-up study." Int. J. Prosthodont. vol. 12. No. 1. 1999.
pp. 65-72. cited by applicant .
Ortorp et al. "Comparisons of precision f fit between cast and
CNC-milled titanium implant frameworks for the dentulous mandible."
Int. J. Prosthodont. vol. 16. No. 2 2003. pp. 194-200. cited by
applicant .
Ortorp et al. "Photogrammetry and Conventional Impressions for
Recording Implant Positions: A Comparative Laboratory Study."
Clinical Implant Dentistry & Related Research. vol. 7. I. 1.
2005. pp. 43-50. cited by applicant .
Ortorp et al. "Screw Preloads and Measurements of Surface Roughness
in Screw Joints: An Invitro Study on Implants Frameworks." Clinical
Implant Dentistry & Related Research. vol. 7. I.3. 2005. pp.
141-149. cited by applicant .
Ortorp. "On titanium frameworks and alternative impression
techniques in implant dentistry." The Sahlgrenska Academy at
Goteborg University. 2005. pp. 1-88. cited by applicant .
Ortorp."Clinical Experiences of Computer Numeric Control-Milled
Titanium Frameworks Supported by Implants in the Edentulous Jaw: A
5-Year Prospective Study." Clin. Implant Dentistry R. Res. vol. 6.
No. 4. 2004. pp. 199-209. cited by applicant .
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injunction case dated May 5, 2011. cited by applicant .
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PCT/SE2007/050565 dated Jan. 22, 2008 (4 pages). cited by applicant
.
Office Action for co-pending U.S. Appl. No. 12/438,683, dated Mar.
10, 2017. cited by applicant.
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Primary Examiner: Afzali; Sarang
Assistant Examiner: Hidalgo-Hernande; Ruth G
Attorney, Agent or Firm: Merchant & Gould P.C.
Parent Case Text
This application is a Continuation of U.S. Ser. No. 12/438,683,
filed 10 Aug. 2010, which is a National Stage Application of
PCT/SE2007/050565, filed 22 Aug. 2007, which claims benefit of U.S.
Ser. No. 60/919,041, filed 20 Mar. 2007, and Swedish Serial No.
0601754-5, field 25 Aug. 2006 and which applications are
incorporated herein by reference. To the extent appropriate, a
claim of priority is made to each of the above disclosed
applications.
Claims
The invention claimed is:
1. A method of manufacturing a dental superstructure comprising a
screw-channel with a first mouth, a screw member seat with a second
mouth, wherein the screw member seat provides support to a head of
a screw member when the screw member extends through the second
mouth to fix said dental superstructure to a spacer element or an
implant, wherein a communication is provided between said first
mouth and said second mouth, the method comprising: drilling said
communication to form at least one central axis of said
screw-channel and a central axis of said second mouth, wherein the
at least one central axis of said screw-channel and the central
axis of said second mouth do not coincide, wherein said drilling
comprises drilling a first straight bore from a first point, and
drilling a second straight bore from a second point, such that said
first bore and said second bore intersect in an interior of said
superstructure to form said communication, and wherein said
drilling comprises drilling a third bore using said first bore and
said second bore as guides, said third bore drilled using a drill
bit with a cutting surface of a sufficient diameter to create said
screw-channel through which said screw member is passed in order to
attach said dental superstructure to said spacer element or said
implant.
2. The method according to claim 1, wherein the drilling of said
first bore and the drilling of said second bore comprises drilling
with a twist drill providing a diameter sufficient for receiving a
threaded part of said screw member.
Description
FIELD OF THE INVENTION
This invention pertains in general to the field of a dental
superstructure and a manufacturing method of said superstructure.
More particularly the invention relates to a superstructure to be
connected to an osseointegrated dental implant. A superstructure of
this kind is disclosed in SE506850.
BACKGROUND OF THE INVENTION
The goal of a dental implant system is to restore the patient to
normal function, comfort, aesthetic, speech and health regardless
of the current oral condition. These implant systems are based on
the implantation of dental implants, such as dental implants made
of biocompatible titanium, through insertion into the patient's
jawbone. In this respect, the use of biocompatible titanium started
in Sweden as early as 1950, and has since then been further
developed and spread world-wide. During the 1980's a number of
implant systems entered the world market. Methods are known in the
art to attach a dental superstructure to an implant. A couple of
methods are based on the use of a screw member. Theses screw
members can attach the superstructure to the implant, either
directly or via spacers.
When implants are implanted in the mouth of a patient who has been
without teeth for some time problems arise due to degeneration of
bone. If a person has been without teeth for some time, the jawbone
that is not under strain of natural teeth or implants, will
dissolve and assimilate over time, yielding less bone material for
the proper anchoring of a dental implant. To find enough bone for
optimal implantation, the implant has to be angled so that the
general axis of the implant projects out of the mouth. Fixing a
superstructure with a screw member in a straight screw channel to
such implants necessitates that the mouth of the screw channel may
be forced to be placed on a visual surface of the dental
superstructure. Also, the optimum placement of the implant, due to
the present dental situation, often results in a non-optimum
placement of the dental superstructure in terms of the patient's
aesthetics, phonetics and bite.
Therefore, there is a need in the dental field for greater freedom
of placement of a dental implant in order to optimize the stability
and success of the implantation, while still achieving good
aesthetics, phonetics and bite of the patient.
Furthermore, in the above mentioned dental situation there is a
need to be able to use an implant placed optimally with regard to
the dental situation, that is, the anatomy of the jawbone, while
still allowing the dental superstructure to be applied in an
optimal way to said implant, such that the mouth of a screw channel
not is visible from outside the mouth of the patient.
The means already known in the art for achieving this goal include
the use of angled spacers and dental superstructures attached to
the implant with adhesive or with other techniques not based on the
use of a screw member. The angled spacers have many drawbacks and
are characterized by adding significant height to the
superstructure, multiple sources of errors, since the coordination
of multiple parts undoubtedly leads this, an unnecessarily high
price, as a result of the multiple parts and multiple manufacturing
steps, increased risk of bacteriological attack, due to the several
corners and surfaces exposable to this, weaker screw for the
attachment of the dental bridge, since no follow-up draft of said
screw is possible since a structure is applied on top of said
angled spacers. It also results in an increased complexity of the
attachment of the superstructure to the implant. U.S. Pat. No.
6,848,908 discloses an arrangement including an angled spacer
element of this kind, including a first passage and a second
passage. The first passage is operative to fasten said spacer
element in an implant, and the second passage is operative to
fasten a superstructure on said spacer element. Superstructures
attached to an implant without using a screw member results in less
strength, difficulties in detachment and also incompatibility
problems with commercially available implant systems of today.
Furthermore, U.S. Pat. No. 5,947,733 discloses a spacer element
with a non-linear bore, connecting a first mouth, intended to be
connected to a dental implant, and a second mouth, intended to be
connected to a dental superstructure through a screw member
engaging with the threaded part (132, 232, 332) of the spacer
element. Thus, also this system is in need of spacer elements at
least for solving the problem of guiding the mouth of a screw
channel, such that it is not visible from outside the mouth of the
patient.
There is therefore a need, among others, for a method of attaching
or detaching a dental superstructure to a dental implant at a
chosen angle without adding additional height to the chosen
superstructure.
Thus, there is a need for a new superstructure that may be fastened
to an implant without angled spacer elements or superstructures
attached to the implant with only adhesive or with other techniques
not based on the use of a screw member. There is also need for a
simpler, faster and cheaper production method of dental
superstructures, while still providing the benefits according to
above. Furthermore, there is a need to provide for the possibility
of a simple assembly ex situ (outside the patient's mouth) and
application in situ (in the patient's mouth).
Hence, an improved superstructure, and a manufacturing method
thereof, would be advantageous, and in particular a superstructure,
and a manufacturing method thereof, allowing for the exclusion of
angled spacer elements or fastening of a superstructure to an
implant by adhesives, without being forced to place the mouth of
the screw channel on a visual surface of the dental superstructure
would be advantageous.
SUMMARY OF THE INVENTION
Accordingly, the present invention seeks to mitigate, alleviate or
eliminate one or more of the above-identified deficiencies and to
provide an improved superstructure of the kind referred to, and a
manufacturing method thereof. For this purpose the superstructure
of this kind is characterized in that a central axis of at least
one part of a screw-channel and a central axis of a mouth of a
screw member seat do not coincide, and the manufacturing method is
characterized by drilling a first bore from a first point of said
superstructure, which first point is intended to face an implant or
spacer element, drilling a second bore from a second point on said
superstructure, which second point is intended to provide a mouth
of a screw channel for attaching said superstructure to said spacer
element or implant.
Advantageous features of the invention are defined in the dependent
claims.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other aspects, features and advantages of which the
invention is capable of will be apparent and elucidated from the
following description of embodiments of the present invention,
reference being made to the accompanying drawings, in which
FIG. 1 illustrates a cross-section of an embodiment of a
superstructure according to the present invention.
FIG. 2 illustrates a cross-section of a first embodiment of a
superstructure according to the principles of the present
invention.
FIG. 3 illustrates a cross-section of a second embodiment of a
superstructure according to the principles of the present
invention.
FIG. 4 illustrates a cross-section of a third embodiment of a
superstructure according to the principles of the present
invention.
FIG. 5A illustrates a side view of a first embodiment of a screw
member according to the principles of the present invention.
FIG. 5B illustrates a side view of a second embodiment of a screw
member according to the principles of the present invention.
FIG. 5C illustrates a side view of a third embodiment of a screw
member according to the principles of the present invention.
FIG. 5D illustrates a side view of a fourth embodiment of a screw
member according to the principles of the present invention.
FIG. 5E illustrates a side view of a fifth embodiment of a screw
member according to the principles of the present invention.
FIG. 6A illustrates a cross-section of a screw driver according to
the principles of the present invention.
FIG. 6B illustrates a partial enlarged view of a portion of the
screw driver of FIG. 6A.
FIG. 6C illustrates a partial enlarged view of a portion of an
alternative embodiment of a screw driver according to the
principles of the present invention.
DESCRIPTION OF EMBODIMENTS
The following description focuses on embodiments of the present
invention applicable to a superstructure, and also to a method of
manufacturing said superstructure.
The present invention discloses, according to FIG. 1, a
superstructure, and a manufacturing method thereof, comprising a
main body, comprising a screw-channel 1 with a first mouth 2,
through which screw-channel 1 a screw member is to be inserted, and
a screw member seat 3 with a second mouth 4, for providing support
to the head of said screw member during fixation of said dental
superstructure to a spacer element or an implant 5 through said
second mouth 4, whereby a communication is obtained between said
first and second mouth, wherein at least one part of a central axis
of said screw-channel 1 differs from a central axis of said second
mouth 4. In this way the mouth 2 of the screw channel 1 may be
located such that the superstructure may be attached/detached to a
dental implant or a spacer element 5 where the mouth 2 of the screw
channel 1 not is visible from outside the patients mouth.
In one embodiment of the manufacturing method of said
superstructure, a superstructure is first manufactured in a way
known to the skilled artisan, and then provided with a
communication according to above. Such a method is for example
disclosed in the Swedish patent SE 509,437, but other manufacturing
methods known to the skilled artisan, such as moulding etc., are
also within the scope of the present invention.
In one embodiment of the present invention the superstructure is,
in contrast to the manufacturing methods according to the prior
art, manufactured with integrated spacer elements, milled from one
single-piece blank, such that the dental superstructure obtains a
main body and spacer elements, wherein said main body and said
spacer elements are integrated. In this context the term integrated
means that the dental superstructure, comprising a main body, and
the spacer elements are consisting of one piece of material, such
that no interface is present in between said superstructure and
said spacer elements. In this superstructure the dimensions of
spacer elements can be varied in accordance with the specific
dental situation of a patient intended to receive said replacement
structure. When the superstructure is applied the spacer elements
will be cooperating with dental implants, inserted and
osseointegrated in bone tissue. To obtain a perfect fit, i.e. no
gap, between the superstructure and the gum tissue, the length and
angle, in respect of the jawbone, superstructure, and jawbone, of
the spacer elements will be individual for each spacer in
respective spacer position.
In one embodiment the material of said superstructure may be
selected from the group comprising titanium, zirconium oxide,
alloys of titanium and zirconium, and other biocompatible
materials, or combinations thereof.
When a superstructure, according to any of the embodiments above,
has been obtained, a superstructure wherein a central axis of at
least one part of a screw-channel differs from a central axis of a
mouth of a screw member seat is provided. In one embodiment this is
obtained, according to FIG. 2, by drilling a first straight bore 21
from a first point 22 on a side of the dental superstructure, at
which first point 22 the mouth of the screw-channel is to be
placed, and a second straight bore 23 from a second point 24 on the
side of the dental superstructure intended to face the implant or
spacer element. It is of course possible to drill the second bore
23 before the drilling of the first bore 21, while still being
inside the scope of the present invention. The first and second
bores are drilled such that they intersect in the interior of the
dental superstructure. Then a third bore 31 may be drilled,
according to FIG. 3, after the drilling of said first bore 21 and
said second bore 23. This third bore may result in a screw-channel.
This third bore may be drilled using said first and second bores as
guides. Said third bore may be drilled by using a drill bit with a
cutting surface of a sufficient diameter to create a bore through
which a screw member may be passed in order to attach the dental
superstructure to a spacer element or an implant 5. The third bore
31, i.e. the screw-channel 1, may preferably be drilled close to
said second point 24, but not the whole way through. Since the
diameter of the third bore 31 is larger than the diameter of said
second bore 23, shoulders 32 will form in the screw-channel 1. Said
shoulders may then form the seat 3 for a screw member head in the
bottom of the screw-channel 1, while being integrated with said
superstructure. Thus, a threaded part of a screw member inserted in
the screw-channel may be passed through said bore, i.e. said second
bore 23, to subsequently attach the dental superstructure to a
spacer element or implant 5. Preferably, the diameter of said
second bore 23 corresponds to the diameter of the threaded part of
the screw member, whereby the screw member may be passed through
said bore to fixate the superstructure to an implant or a spacer
element 5. Thus, a dental superstructure comprising a main body,
comprising a screw-channel 1 with a first mouth 2, through which
screw-channel 1 a screw member is to be inserted, and a screw
member seat 3 with a second mouth 4, for providing support to the
head of said screw member during fixation of said dental
superstructure to a spacer element or an implant 5 through said
second mouth 4, may be obtained. Hereby a communication is obtained
between said first mouth 2 and said second mouth 4. By providing a
central axis of at least a part of said screw-channel 1 and a
central axis of said second mouth 4 that do not coincide, one may
guide the position of said first mouth 2, i.e. through which a
screw member is to be inserted, into a position that optimizes the
arrangement of the superstructure. This may for example be to
locate said first mouth 2 in an aesthetically pleasing position,
such as on a surface of the superstructure that can not be seen
from outside the mouth of the patient. It is also possible that
only the direction of the central axis of a part of the
screw-channel 1 differs from the direction of the central axis of
the mouth 4 of the screw member seat 3, in accordance with FIG. 1,
while still being inside the scope of the present invention.
In one embodiment of the present invention the central axis of said
first mouth 2 and the central axis of said second mouth 4 do not
coincide.
In one embodiment the first bore 21 and the second bore 23 are made
with a conventional twist drill. In this way the first bore 21 and
the second bore 23 are drilled to a diameter of a suitable size for
passing of the threaded part of a screw member, which screw member
is used for attaching the superstructure to a spacer element or
implant 5. It is also possible to drill said second bore 23 using a
drill bit with a cutting surface of a sufficient diameter to create
a bore through which a screw member may be passed in order to
attach the dental superstructure to a spacer element or an
implant.
It is also possible to drill said third bore all the way through
said first bore, in accordance with FIG. 4. Then a separate seat 41
for the screw member head may subsequently be inserted and attached
to said superstructure. This may be done by attachment techniques
known in the art, such as welding or attachment by known adhesive
agents. It is even possible to only drill one bore, with a diameter
through which a screw member may be passed in order to attach the
dental superstructure to a spacer element or an implant. This bore
may extend all the way from said first point 22 to said second
point 24, or it may extend to a close proximity to said second
point 24. If said one bore extends all the way from said first
point 22 to said second point 24, a separate seat 41, comprising a
hole 42 for matching the threaded part of a suitable screw member,
for the screw member head may subsequently be inserted and attached
to said superstructure by attachment techniques known in the art,
such as welding or attachment by known adhesive agents. If said one
bore do not extend all the way from said first point 22 to said
second point 24, a bore, matching the threaded part of the screw
member, may be drilled from said first point 24, i.e. the point
intended to face the dental implant or a spacer element 5, whereby
the screw member seat 3 and the second mouth 4 are created,
according to the teachings above. By providing a central axis of at
least a part of said one bore and a central axis of said bore,
matching the threaded part of the screw-member, or said hole, for
matching the threaded part of a suitable screw-member, that do not
coincide, one may guide the position of a mouth of said one bore,
i.e. through which a screw member is to be inserted, into a
position that optimizes the arrangement of the superstructure.
An example of a separate seat 41 may be a ring with an outer
diameter corresponding to the inner diameter of the screw-channel 1
of the superstructure, and an inner diameter corresponding to the
threaded part of the screw member, intended to be used when
fixating the superstructure to a spacer element or an implant
5.
In yet another embodiment of the present invention the
superstructure is provided with a dental implant seat or a spacer
element seat, such as a recess suitable for receiving a protrusion
on said dental implant or spacer element. It is of course also
possible to provide the superstructure with a protrusion and the
dental implant or spacer element with a recess, as long as the
seating effect is obtained. This dental implant seat or a spacer
element seat provides the advantage of easier assembling of the
superstructure on a dental implant or a spacer element.
In one embodiment of the present invention the drill bit used, with
a cutting surface of a sufficient diameter to create a bore through
which a screw member may be passed, i.e. a screw-channel, such as
the drill bit used when drilling said third bore, may have a
declining cutting surface, such as an arched, semi-spherical, or
spherical cutting surface. In this way the bottom part of the
screw-channel may have a declining shape, such as an arched or
semi-spherical. Thus, the bottom part may fit with a screw member,
according to FIGS. 5A-5E, with a bevelled screw member head 51,
arched screw member head 51a, a half-spherical screw member head
51b, spherical screw member head 51c or semi-spherical screw member
head 51d and a threaded part 52. Hereby, the diameter of the
beveled screw member head 51 may decline, in an arched way, along
with a surface 53 intended to, in use, bear upon the shoulders of a
screw member seat, from the diameter of the beveled screw member
head 51 to approximately a diameter of a threaded part 52 of the
screw member. A screw member with a beveled, such as arched,
spherical or semi-spherical head may also follow a screw-channel 1
according to the invention. The arched, spherical, or
semi-spherical screw member heads 51a, 51c, 51d of the screw member
may in this way act as a guide for guiding the screw member from
the mouth 2 of screw-channel, i.e. said first point 22, to a seat 3
in the bottom of said screw-channel 1. This seat also comprises
said second bore 23, through which the threaded part of the screw
member may be passed to attach said superstructure to a spacer
element or implant 5. The screw member with a spherical screw
member head 51c or semi-spherical screw member head 51d also
provides a higher fixing strength and self-centering properties.
Since the surface 53 bearing on the shoulders of the screw member
seat 3 is arched, such as spherical or semi-spherical, a greater
contact surface between the screw member and the shoulders 32 of
the screw member seat 3 is obtained. Thereby, the fixating strength
obtained from the fixation of the superstructure to the dental
implant 5 may be greater than if the surface bearing on the
shoulders of the screw member not was arched. The screw member is
provided with a recess for receiving a driving means, such as a
screwdriver. This recess may be a score, or a slit. The recess may
also have other shapes, corresponding to a screwdriver, such as a
starshape or a recess with a number of sides, such as tri-tetra-,
penta-, or hexagonal. It is of course within the present invention
to provide such a recess in any other shapes corresponding to a
matching male part on a screwdriver or other driving means. Thus, a
screw-member, comprising a threaded part and a screw-head with a
recess for receiving a driving means, such as a screwdriver, said
screw-head comprising a surface bearing, in use, on shoulders of a
screw-member seat, wherein said surface is bevelled towards the
threaded part, has been described.
It is also within the present invention to drill said third bore
with drilled bits having cutting surfaces with other declining
and/or bevelled shapes, such as cone shaped.
The screw member may be fixed with a screwdriver, in accordance
with FIG. 6a, comprising a rotatable handle portion 61 and a
flexible and/or bendable shaft portion 62, with a distal end 63
coupled to said handle portion 61 and a proximal end 64 coupled to
a tip 65 for driving said screw member with rotation transmitted
from said rotatable handle portion 61. Such a screwdriver, for
fastening screw members in a screw-channel described above, may
comprise a flexible and/or bendable shaft 62. This flexible shaft
62 may in one embodiment comprise twinned wires 66, giving a high
torque capacity, independent of shaft bending and angle to the
screw member. Said flexible shaft portion 62 may comprise a
plurality of wires 66, said wires being twinned in a plurality of
layers, in accordance with FIG. 6b, such that said flexible shaft
62 is formed between said distal end 63 and said proximal end 64.
The plurality of layers may be twinned such that one part of the
layers is twinned in one direction while the other part of the
layers is twinned in the other direction. Since said screwdriver
has twinned layers of wires, in accordance with FIG. 6b, in two
directions the screwdriver is provided with torque capacity in both
rotational directions of said flexible shaft. In one embodiment the
number of twinned layers may be uneven, whereby the uneven number
of layers are twinned in a direction giving the screwdriver a
unfastening torque capacity while the even number of layers are
twinned in a direction giving the screwdriver a fastening torque
capacity. The number of layers may for example be selected within
the interval of 2 to 30, such as 10 to 20, but this interval is
only intended to be interpreted as guidance and not as limiting. Of
course, it is possible to construct screwdrivers with a number of
twinned layers outside the given interval, which still may obtain
the intended effect. The torque capacity of such a screwdriver may
be at least 30 to 35 Ncm.
In one embodiment the screwdriver is provided with a flexible
and/or bendable core, in accordance with FIG. 6c, in said shaft,
onto which the plurality of wires are twinned. This flexible and/or
bendable core may for example be manufactured of an ordinary
plastics or rubber, fulfilling the desired features according to
flexing and/or bending in respect of being able to flexate or bend
in the screw channel.
In one embodiment the rotatable handle portion 61 and a flexible
and/or bendable shaft portion 62 of the screwdriver are separable.
In this embodiment the flexible and/or bendable shaft portion 62
may first be inserted in the screw-channel 1, and thereafter the
rotatable handle portion 61 is mounted and fixed to said flexible
and/or bendable shaft portion 62. Thereby, it may be easier to
access the screw member in the screw-channel 1, if the central axis
of the screw-channel and the central axis of the second mouth
differs in a high degree.
The elements and components of an embodiment of the invention may
be physically, functionally and logically implemented in any
suitable way. Indeed, the functionality may be implemented in a
single unit, in a plurality of units or as part of other functional
units. As such, the invention may be implemented in a single unit,
or may be physically and functionally distributed between different
units and processors.
Although the present invention has been described above with
reference to specific illustrative embodiments, it is not intended
to be limited to the specific form set forth herein. Rather, the
invention is limited only by the accompanying claims and other
embodiments than the specific above are equally possible within the
scope of these appended claims.
In the claims, the term "comprises/comprising" does not exclude the
presence of other elements or steps. Furthermore, although
individually listed, a plurality of means, elements or method steps
may be implemented by e.g. a single unit or processor.
Additionally, although individual features may be included in
different claims, these may possibly advantageously be combined,
and the inclusion in different claims does not imply that a
combination of features is not feasible and/or advantageous. In
addition, singular references do not exclude a plurality. The terms
"a", "an", "first", "second" etc do not preclude a plurality.
Reference signs in the claims are provided merely as a clarifying
example and shall not be construed as limiting the scope of the
claims in any way.
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